clark



N. D. CLARK. LOOPER THREAD CONTRULUNG MECHANISM. APPLICATION HLED 02031.1914.

1,289,663. Patented Dec. 31. 1918.

4 SHEETS-SHEET I.

N. D. CLARK.

LOOPER THREAD CONTROLLING MECHANISM.

APPLICATION FILED DEC. 3!- I914.

Patented Dec. 31, 1918.

SHEETS-SHEET 2 yawn N D. CLARK,

LOOPER THREAD CONTROLLING MECHANISM.

APPLKCATION FILED 05c. 31. 1914.

1,289,663. Putentvd Dec. 31, 1918.

4 SHEETS SHEET 3.

N. D. CLARK.

LOOPER THREAD CONTROLLING MECHANISM.

APPLICAHON LED DEC. 3!,1914- 1,289,663. Patented Dec. 31, 1918.

"rSHEETS-SHEET 4.

WWW: 16 03. 6 4

UNITED STATES PATENT OFFICE.

NELSON D. CLARK, OF CHICAGO, ILLINOIS, ASSIGNOR TO UNION SPECIAL MACHINE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

LOOPER-THREAD-CONTROLLING MECHANISM.

Specification of Letters Patent.

Patented Dec. 31, 1918.

Application filed December 81, 1914. Serial No. 879,824.

To all whom it may concern:

Be it known that I, NELSON D. CLARK, a citizen of the United States, residin at Chicago, in the county of Cook, State 0 Illinois, have invented certain new and useful Iniprovements in Looper-Thread-Controlling Mechanism, of which the following is a do scription, reference being had to the accompanying drawing and to the figures of reference marked thereon.

The invention relates to new and useful improvements in thread controlling mechanism for the looper of a seivingmachine,

and more particularly to a thread controlling mechanism for a sewing machine having a cylindrical work support in which the looper operates.

An object of the invention is to provide a thread controlling mechanism which may be placed within the cylindrical support and operated from the looper operating mechanism.

A further object of the invention is to provide a looper mechanism of the above character, wherein the movable parts operating on the looper thread are oscillating parts so as to avoid the entangling of the thread of the looper, if the same should be broken.

A further object of the invention is to provide a thread controlling mechanism, where in the thread may be clamped between the supply and the looper and a double acting pull-ofi mechanism caused to engage the thread between the clamp and the supply for pulling the thread at the desired time to be subsequently furnished to the looper.

These and other objects will in part be obvious and will in part be hereinafter more fully described.

In the drawings which show by way of illustration one embodiment of the invention Figure 1 is a view partly in side elevation and partly in section of a sewing machine embodying my improved thread 'ontroller;

Fig. 2 is a plan view of the cylindrical bed plate with the cover removed, showing the feeding mechanism. looper mechanism and thread controlling mechanism in plan Vlev I Fig. 3 is a detail in side elevation, showing the looper shaft and the thread ling devices operated thereby;

Fig. 4 is a sectional view on the line 44 of Fig. 3;

Fig. 5 is an enlarged detail view, showing the rear side of the thread controlling arm, the thread clamps and the position of the same in the work support;

Fig. 6 is a sectional view through the work support on the line 6-6 of Fig. 5;

Fig. 7 is a detail, partly in plan and partly in section, showing a portion of the looper shaft, the thread controlling devices and the actuating niechanism therefor;

Fig. 8 is a detail, showing the looper supporting shaft, the looper and the needles and the relation of the same to the work support;

Fig. 9 is a detail, showing a section of the work support and the looper, with the looper at the rear end of its stroke;

Fig. 10 is a similar view, showing the looper at the forward end of its stroke;

Fig. 11 is a diagrammatic view, showing the position of the thread controller when the looper is at the forward end of its stroke;

i Fig. 12 is a similar view, showing the position of the thread controller when the looper is at the rear end of its stroke;

Fig. 13 is a detail. showing in side elevation, the thread engaging member which engages the thread between the looper and the thread clamps.

I have shown my invention as applied to a sewing machine, which consists of a supporting standard 1, carrying an overhanging arm 2. in which reciprocates a needle bar 3, carrying two spaced needles 4 4. This needle bar is reciprocated in the needle head by a needle lever which is operated from the main shaft 5 which extends transversely of the work support and is located in the standard 1. Also mounted in the overhanging arm is a presser bar 6 which carries a presser foot 7.

Cooperating with the presser foot 7 is a feed dog 8, which is so positioned as to feed the material up the arm of the machine. The feed dog is carried by a feed bar 9 which is reciprocated back and forth by a controllink 10. Said feed bar is raised and lowered by a frame 11, coo crating with an eccentric on the looper shaft Cooperating with the needles beneath the work support is a looper 12. This looper 12 is fixed to the forward end of the looper shaft 13. The looper shaft is operated from the main shaft 5 by suitable devices which move the looper shaft endwise and also oscillate the looper shaft to move the looper into and out of the needle loops.

The present invention is directed articularly to the looper thread controlling devices. The looper thread is passed from the supply through a tension 14 and thence through a guiding tube 15 to the inside of the cylindrical work supporting arm 16', which carries the feeding mechanism and the looper mechanism, above referred to. Mounted in the cylindrical work support is a cross-shaft 16. This cross shaft carries an arm 17 which projects toward the rear of the machine and on which is mounted two spaced thread guides 18 and 19. The arm 17 is provided with a socket in its outer end and the thread guides 18 and 19 are carried by a bracket 17*, having a shank tending into the socket in the arm 17. Screws 17 secure said shank in said socket. By loosenin the screws 17 the brackets 17 ma v be OSCllTfltQtltll'ldthlS will shift the position of the guides 18 and 19. The guides 18 and 19 are also mounted in the socket in the bracket 17 and held therein by screws 17 and 17 respectively. By loosening these screws the guides 18 and 19 may be turned and their angular position relative to the supporting bracket varied. The looper thread, indicated at 1, passes from the guiding tube 15 through these thread guides 18 and 19. The cross-shaft 16 is provided withan arm 20. The looper shaft 13 carries an arm 21. A link 22 is connected to a ball stud on the arm 21 and also to a ball stud on the arm 20 of the cross shaft 16. As the looper shaft is oscillated, the arm 20 will be oscillated. which will in turn oscillate the cross-shaft 16 and swing the arm 17 carrying the thread guides 18 and 19 up and down. Mounted on the work support is a. bracket 23. which carries "a thread guide 24. The looper thread after leaving the thread guide 19 passes through the thread guide 24.

In Figs. 3 and 11, I have shown the arm 17 at the lower end of its oscillation and in this position the thread guides 18 and 19 are at a considerable distance below a line drawn through the end of the tube 15 and the stationary thread guide 24. In this position the maximum amount of looper thread has been pulled off by said thread guides 18 and 19. These thread guides will more when the cross-shaft is oscillated to a position indicated in Fig. 12, where said thread guides are substantially in line with the dc 24 and the thread guiding tube 15. Mounted on the looper shaft 13 1s a sleeve 25 which carries a cam-shaped projection 26. This cam-shaped projection 26 extends between the thread guides 18 and 19. Said projection is so timed that when the thread guides are lowered for pullin thread from the supply, the projection will engage the thread between the guides 18 and 19 and will pull an additional amount of thread from the supply. When the thread guides are moving in the opposite direction, said projection rides over the thread, and has no effect thereon, as the thread guides 18 and 19 are at this time moving upward. The thread engaging the member 26 is carried over the end thereof and released during a movement of the member 26 in each direction.

After passing through the fixed guide 24 the thread passes between thread clamps 27. These thread clamps are shown in detail in rig. 6 of the drawing. Said clamps consist of two members 28 and 29. These two members are yieldingly mounted and are normally held separated so as to allow the thread to pass freely between the two clamping members when they are released. The

arm 17 extends to the other side of the cross shaft and mounted on said arm is a roller 30. This roller 30 is positioned so as to engage the outer face of the clamping member 29. Said outer face of the clamping member is provided with a shoulder 31. As clearly shown in Fig. 6, when the arm is in its lower position, the thread clamps are released. When, however, the arm is raised from this position, the roller will engage the shoulder and cause the thread to be clamped, releasing the same when the roller reaches its extreme position above the shoulder 31.

Mounted on the bracket 23 are two thread guides 32 and 33. The looper thread after passing the thread clamps is led through these guides. On the end of the arm 17, which projects to the right of the crossshaft 16, and viewed in Figs. 3 and 7, there is a projecting plate 34, which extends between the thread guides 32 and 33 and engages the thread assing through said guides. This projecting plate has a rounded nose which engages the thread and releases th same durlng each movement of said plate. The plate is so timed as to engage the looper thread when the thread clamps are closed and when the looper is being retracted. Said projecting plate will take up the looper thread at this time and aid in holding the ooper thread between the eye of the looper and the previous stitch taut, so as to insure that the needles will pass into the thread triangle in the formation of the stitch. The looper thread after messes leaving the thread guide 33 passes through an opening 35 in the front bearing block of the work upport and thence to the rear eye 36 of the looper 12. This opening 35 has a rounded shoulder 37 against which the looper thread is drawn when the looper moves forward. When the looper is retracted, the looper thread is moved out of contact with said shoulder, as clearly shown in Fig. 9 of the drawings. This rearward movement of the looper will pull on the looper thread as the looper is moving in a direction transversely to the travel of the looper thread as it passes along the side of r the work support. As above noted, the camshaped projecting plate 34 engages the thread passing through the thread guides 32 and 33 on its upward movement as well as on its downward movement. This member is so timed as to engage the looper thread just before the point of the looper enters the needle loops and this takes up the slack in the looper thread andpmvents the same from buckling in front of the looper or being twisted about the shank of the loo er on the drawing up of the needle loops. y adjusting the bracket 17 the position of the guides 18 and 19, relative to the cam-shaped pi'ojection 26 may be varied and thus the amount of thread pulled off adjusted. The operation of my improved thread controller is as follows: a

When the looper is at the rear end of its stroke, the thread guides 18 and 19 are at the upper end of their stroke, as shown in Fig. 12. At this time the thread clamps are open and the thread engaging plate 34 is out of contact with the looper thread. As the looper moves forward, the looper thread will first be slackened. The continued forward movement of the looper carries the beak of the looper into the needle loops drawn out of the needles as they tart to rise. The thread engaging late 34 engages the looper thread just before the point of the looper enters the needle loops and takes up the slack in the looper thread, as above noted. The continued forward movement of the looper oscillating the looper shaft will in turn oscillate the cross shaft 16 which will cause the roller 30 to close the thread clamps and grip the thread at this point. The continued movement of the looper forward causes the thread guides 18 and 19 to move downward, also the thread cam 26 to move upward, and these thread guides and the cam cooperate in pulling on the looper thread to draw the looper thread from the upply. Inasmuch as the thread clamps are closed at this time, the drawing of the thread from the supply will in no way interfere with the handling of the thread by the looper. The continued forward movement of the looper to the end of its stroke moves the thread controlling arm 17 so as to bring the cam plate 34 above the looper thread and also the roller 30 above the shoulder on the thread clamps and release the thread clamps. The looper may at this time draw a little thread if needed from the thread which has been pulled off from the supply. As the looper starts to retract, the thread clamps are again closed and the cam plate 3f engages the looper thread between the guides 32 and 33 and pulls up on the thread at this time. This pulling of the thread occurs just before the points of the needle pass the looper thread and aid in holding the looper thread taut between the eye of the looper and the previous stitch. The looper thread, as the looper reaches the forward end of its stroke, is drawn against the shoulder 37, and as the looper is retracted it is moved out of engagement with this shoulder and the slack formed in the looper thread through this retracting movement of the looper is taken up by this cam plate 34, as above described. When the looper reaches the rear end of its stroke, the needles are down, the stitch is set, and the looper thread is consequently drawn on, as clearly hown in Fig. 9, and this pulls the looper thread through the thread clamp, which is open at this time, and from the thread guides 18 and 19, which are now giving up the slack thread.

From the above description, it will be apparent that I have provided a looper thread controlling mechanism, wherein all the parts operating upon the thread oscillate in their movements and therefore, if the looper thread should be broken, it will not be wound up or entangled, as is likely to occur where the looper thread controlling parts rotate.

It will also be noted that I have packed my entire looper thread controlling mechanism in the cylindrical work support and that the moving parts are positively actuated from the looper shaft, and therefore said parts will move in proper timing with the movements of the looper. I prefer to use a looper mechanism wherein the looper 1s 'ven an extended -dwell at the forward en of its stroke, so that said looper may have a relatively short stroke and so as to avo 1d excessive pull on the looper thread which is liable to pucker the material being stitched. By operating the thread control ling mechanism directly from the oscillating movements of the looper shaft. I am able to give to the thread controlling mechanism a similar dwell while the looper is at a dwell. By the use of the thread cam which cooperates with the thread guides in pulling the thread from the supply, I am able to pull a sufficient amount for the formation of the stitch without giving the thread pullin device an excessive movement, which won d be impracticable where the parts are housed in a cylindrical work support, as there is no room in the cylindrical work support for extended movements of the thread engaging devices.

t is obvious that minor changes may be made in the construction and arrangement of arts without departing from the spirit of t e invention as set fort in the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. The combination of a standard, a cylindrical work support carried by said standard and projecting therefrom, a looper shaft mounted in said cylindrical work support, a looper carried thereby, a thread controlling mechanism for the looper thread located in said cylindrical work support including a cross-shaft mounted in the cylindrical work sup ort, an arm carried thereby and extending ongitudinally of the cylindrical work su port, a thread engaging member carried K said arm, thread guides for guiding the t read into cooperative relation with said thread engaging device, a second armcarried by said cross-shaft, and means operated'by the looper shaft and connected to said last-named arm for oscillating the same.

2. The combination of a standard, a cylindrical work support carried by said standard and projecting therefrom, a looper shaft mounted in said cylindrical work support, a looper carried thereby, a thread controlling mechanism for the looper thread located in said cylindrical work su port including a cross-shaft mounted in t e cylindrical work support, an arm carried thereby a thread engaging member carried by said arm, thread guides for guiding the thread into cooperative relation with said thread engaging device, a second arm carried by said cross-shaft an arm carried by the looper shaft, a ball stud mounted on said arm, a link for connecting said ball stud to the arm on the cross-shaft for oscillating the same.

3. The combination of a standard, a cylindrical work support carried by said standard and projecting therefrom, a looper shaft mounted in said cylindrical work support, a looper carried thereby, a thread controllin mechanism for the loo er thread locate in said cylindrical wor support, and including thread clamps, an oscillatin arm, a thread engaging device carried t ereby for engaging the looper thread between the thread clamps and the looper, a second oscillating arm, a thread engaging device carried thereby for engaging the looper thread be tween the thread clamps and the supply, and means for oscillating said thread arms from said looper shaft.

4. The combination of a standard, a cylindrical work support carried by said standard and projecting therefrom, a looper shaft mounted in said cylindrical work support, a looper carried thereby, a thread controlling mechanism for the looper thread located in said cylindrical work support, including thread clamps, an oscillatin arm, a thread engaging device carried t ereby for engaging the looper thread between the thread clamps and the looper, a second oscillating arm, a thread engaging device carried thereby for engaging the loo er thread between the thread clamps and the supply, a cross-shaft mounted in said cylindrlcal work support on which said arms are rigidly mounted, and means for oscillating said cross-shaft from said looper shaft.

5. The combination of a standard, a cylindrical work support carried by said stand ard and projecting therefrom, a looper shaft mounted in said cylindrical work support, a looper carried thereby, a thread controlling mechanism for the looper thread located in said cylindrical Work support, including thread clamps, an oscillating arm, a thread engaging device carried thereby for engaging the looper thread between the thread clamps and the looper, a second oscillating arm, a thread engaging device carriedthereby for engaging the looper thread between the thread clamps and the supply, a crossshaft mounted in said cylindrical work support on which said arms are rigidly mounted, a thread arm carried by said cross-shaft, a' ball stud mounted thereon, an arm carried by the looper shaft, a ball stud mounted thereon, and a link connecting said ball studs.

6. The combination of a standard, a cylindrical work support carried by said standard and projecting therefrom, a looper shaft mounted in said cylindrical work support, a looper carried thereby, a thread controlling mechanism for the looper thread located in said cylindrical work support including thread clamps, an oscillating arm, a threa engaging device carried thereby for engaging the looper thread between the thread clamps and the looper, a second oscillating arm, a thread engaging device carried thereby for engaging the looper thread between the thread clamps and the supply, a cross shaft mounted in said cylindrical work support on which said arms are rigidly mounted, means for oscillating said cross-shaft from said looper shaft, and a roller mounted on the arm carrying the thread engaging device for engaging the looper thread between the thread clamps and the looper for closing said thread clamps.

7. The combination of a standard, a cylindrical work support carried by said standard and projecting therefrom, a looper shaft mounted in said cylindrical work support, a looper carried thereby, a thread controlling mechanism for the looper thread located in said cylindrical work support and including thread clamps between the looper and the supply, an arm, thread guides carried by said arm and engaging the looper thread between the thread clamps and the supply, and means for oscillating said arm from the looper shaft, said looper shaft having a cam shaped projection for engaging the looper thread between said thread guides.

8. The combination of a standard,a cylindrical work support carried by said standard and projecting therefrom,a looper shaft mounted in said cylindrical work support, a looper carried thereby, a thread controlling mechanism for the ooper thread located in said cylindrical work support and including a thread clamp for engaging the thread between the supply and the looper, a crossshaft, an arm carried by the cross-shaft, spaced thread guides mounted on the arm and engaging the looper thread between the thread clampand the supply, a second arm carried by the cross-shaft and projecting therefrom in the same direction as the first named arm, means for connecting said second arm to the looper shaft for oscillating the same, a cam shaped projection carried by the looper shaft for engaging the looper thread between said thread guides, said cam shaped projection being located on the opposite side of the looper shaft from the con nection between the looper shaft and the arm, whereby said cam shaped projection oscillates in a direction opposite to the thread guides when pulling on the thread.

9. The combination of a standard, a cylindrical work support projecting therefrom, a looper mounted in said work support, a pull-ofi' for the looper thread includlng oscillating thread guides mounted in said cylindrical work support, an oscillating thread engaging member for engaging the thread between said guides, and means for oscillating said devices, whereby said thread engaging member is moved in a direction op osite to the thread guides when pulling't read from the supply.

10. The combination of a looper and a thread controller therefor, including oscillating thread guides, and an oscillating thread engaging member for engaging the thread between said guides, a bracket carrying said oscillating thread guides, an arm to which said bracket is connected, means for oscillating said arm, and means whereby said bracket may be adjusted on said arm for varying the position of the thread guides relative to said thread engaging member.

' In testimony whereof, I aflix my signature in the presence of two witnesses.

NELSON D. CLARK.

Witnesses:

HAROLD C. EDWARDS, GEORGE TATE. 

